1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming system with a user authentication function, as well as an authentication device.
2. Related Art
Recently, multifunction peripherals (MFP) having functions of scanner, facsimile machine, printer, copy machine and the like are used in offices and the like. Such multifunction peripherals are often used in a state of being connected to an information processing terminal such as a personal computer via a network such as a LAN (Local Area Network). The multifunction peripherals function as: an image forming apparatus that prints image data inputted from the information processing terminal on paper; an image reading apparatus that obtains image data used in the information processing terminal; and a document management apparatus that accumulates document image data so as to be searchable.
Such image data outputted from the information processing terminal and inputted to the multifunction peripheral for printing may be highly confidential and may require protection from prying. In addition, in an environment in which a plurality of information processing terminals are connected to a multifunction peripheral, the information processing terminals are often installed away from the multifunction peripheral. Therefore, in a case in which the information processing terminal instructs the multifunction peripheral to print highly confidential image data, there is a possibility that printed matter outputted by the multifunction peripheral may be seen and taken away by other users of the multifunction peripheral.
In view of such a situation, a multifunction peripheral having a private printing function is proposed (Related Art 1). In Related Art 1, in order to perform private printing, a user submits image data along with a password to the multifunction peripheral from the user's information processing terminal. Next, the user moves to a location of the multifunction peripheral, where the user logs in to and instructs the multifunction peripheral to execute a printing job of the image data submitted in advance. In response to the user's instruction, the multifunction peripheral prompts the user to input the password that is set to the printing job. When the user inputs the password to the multifunction peripheral, the multifunction peripheral executes the printing job.
In such a multifunction peripheral having an authentication function for confirming the user's usage permission, if the user leaves the multifunction peripheral without logging out, there is a possibility that other people not having usage permission may use the multifunction peripheral. In addition, in a case in which the multifunction peripheral has a document management function, there is a danger that highly confidential document image data accumulated in the multifunction peripheral may be seen by a third party. In particular, printing jobs for private printing as described above are stored in a document box accessible to the user. The document box is password-protected from access by other users having usage permission for the multifunction peripheral. If a user forgets to log out with such a configuration, other printing jobs remaining in the box will not be executed as long as the password is unknown; however, other data in the document box of the user is accessible to anyone.
Various proposals have been made in order to address a situation where a user forgets to log out. For example, a technology is disclosed for automatically logging out upon the elapse of a predefined expected operation period and an input standby period (Related Art 2). In addition, for a function of forced logout in a case in which a user does not perform any operation for a predetermined time period (auto-logout period), a technology is disclosed for managing the auto-logout period for each user and reducing the auto-logout period for users to whom an auto-logout function has been activated (Related Art 3). Furthermore, a technology is disclosed for reserving a predetermined job and automatically logging out upon completion of the reserved job (Related Art 4).
However, the abovementioned techniques for preventing forgetting to logout are not satisfactory due to the following problems.
In the technology disclosed in Related Art 2, due to automatic logout upon elapse of the predefined expected operation period and the input standby period, a user may be logged out during operation, if the user takes time to perform the operation for some reason. This forces the user to log in again and repeat the operation from the beginning. Such a situation reduces operability and therefore is not preferable.
In the technology disclosed in Related Art 3, a user with a reduced auto-logout period may be logged out during operation if the user does not smoothly perform operations. Recent multifunction peripherals have a variety of functions, some of which are rarely used by users. In a case of using such functions, users cannot necessarily smoothly perform operations. As a result, the user may be forced to log out during operation and operability may be reduced as in the technology of Related Art 2.
The technology disclosed in Related Art 4 is cumbersome, since, on completion, a reservation must be made for the job of executing a logout process. Especially in a case of successively performing a plurality of jobs, an assumption must be made for the last job and, if the order of jobs is changed, a user may be logged out during operation. Although Related Art 4 discloses a configuration in which a reservation is made during processing of a job, if a user forgets the reservation, forgetting to logout cannot be prevented.